JP7086302B2 - Electric vehicle control device - Google Patents

Description

The present invention relates to an electric vehicle control device that controls a plurality of induction motors with one inverter.

Ground elements, which are receivers for various traffic lights, are placed on the track on which the electric vehicle travels. In order to prevent these ground elements from malfunctioning, electric vehicles have regulations on leakage noise. In Patent Document 1 below, in order to suppress common mode noise, a hollow core made of a ferromagnetic material such as ferrite or amorphous metal is arranged around the wiring between the inverter and the motor which is the load. It is stated that it should be done.

Japanese Unexamined Patent Publication No. 2004-187368

However, the space under the floor of electric cars is limited. Therefore, there may not be sufficient space for adding a filter component such as the core described in Patent Document 1. In such a case, the specifications of the electric vehicle control device may have to be reviewed in order to secure a space for additional filter parts.

Further, the filter characteristics of the filter component need to be determined according to the impedance including the induction motor. However, the manufacturer of the induction motor and the manufacturer of the electric vehicle control device are not always the same. In this case, relying on the addition of filter parts increases the design man-hours for the manufacturer of the electric vehicle control device and increases the adjustment work in the actual vehicle. Therefore, it is desired to suppress leakage noise without relying on the addition of filter parts.

The present invention has been made in view of the above, and an object of the present invention is to obtain an electric vehicle control device capable of suppressing leakage noise without relying on the addition of filter parts.

In order to solve the above-mentioned problems and achieve the object, the present invention is an electric vehicle control device that controls a plurality of induction motors with one inverter. The electric vehicle control device includes a first inverter for controlling a first electric motor group composed of a plurality of induction motors, and a second inverter for controlling a second electric motor group composed of a plurality of induction motors. The induction motors belonging to the first electric motor group are mounted on different trolleys, and the induction motors belonging to the second electric motor group are mounted on different trolleys. The first inverter and the induction motor belonging to the first electric motor group are connected by the first conductor, and the second inverter and the induction motor belonging to the second electric motor group are connected by the second conductor. .. The first length, which is the distance between the centers of the first conductor and the second conductor between each of the first and second inverters and the trolley, is the conductor portion in the cross section of the first conductor. It is three times or less the average value of the second length, which is the maximum length, and the third length, which is the maximum length of the conductor portion in the cross section of the second conductor.

According to the electric vehicle control device according to the present invention, there is an effect that leakage noise can be suppressed without relying on the addition of filter parts.

The figure which shows the circuit structure of the electric vehicle control device which concerns on Embodiment 1. The figure which shows the circuit structure of the conventional general electric vehicle control device. The figure which shows the arrangement example of the conventional general induction motor in an electric vehicle The figure which shows the configuration example of the conventional general inverter main circuit The figure used to explain the method of generating the pulse width modulation ( PWM ) control signal applied to the semiconductor element of each arm shown in FIG. The figure which shows the PWM control signal generated by each phase voltage command shown in FIG. The figure which shows the equivalent circuit of FIG. 2 used for the explanation of leakage current. The figure which shows the common mode voltage generated by the PWM control signal shown in FIG. The figure which shows the structural example of the inverter main circuit which concerns on Embodiment 1. The figure which shows the arrangement example of the induction motor in Embodiment 1. The figure used for explaining the variation of the voltage command given to the leg of each group and each phase in Embodiment 1. The figure which shows the PWM control signal generated by each phase voltage command shown in FIG. 11A. The figure which shows the equivalent circuit of FIG. 1 used for the explanation of the leakage current in Embodiment 1. The figure used for explaining the distance between conductors in Embodiment 1. The figure which shows the circuit structure of the electric vehicle control device which concerns on the comparative example of FIG. The figure which shows the arrangement example of the induction motor different from FIG. 10 in Embodiment 1. The figure which shows the arrangement example of the cooler in Embodiment 1. The figure which shows the structure in the vehicle of the electric vehicle control device which concerns on Embodiment 2. The figure which shows the structure in the vehicle of the electric vehicle control device which concerns on the modification of Embodiment 2. The figure which shows the structure around the bogie of the electric vehicle control device which concerns on Embodiment 3. The figure which shows the structure of the inverter connection part in the electric vehicle control device which concerns on Embodiment 4. A block diagram showing an example of a hardware configuration that realizes the functions of the control unit according to the first to fourth embodiments. A block diagram showing another example of a hardware configuration that realizes the functions of the control unit according to the first to fourth embodiments.

The electric vehicle control device according to the embodiment of the present invention will be described in detail with reference to the accompanying drawings. The present invention is not limited to the following embodiments. Further, in the attached drawings, the scale of each part may differ from the actual scale. The same applies between the drawings.

Embodiment 1.
FIG. 1 is a diagram showing a circuit configuration of an electric vehicle control device according to the first embodiment. As shown in FIG. 1, the electric vehicle control device 10 according to the first embodiment includes a capacitor 11, a first inverter 12 ₁ , a _second inverter 122, and a control unit 20. The first inverter 12 ₁ is connected to two induction motors 18 ₁ and 18 ₂ belonging to the _{first motor group 16 1 by} a first conductor 141. The _second inverter 122 is connected to _two induction motors ₁₈₃ and 184 belonging to the _second motor group 162 by a _second conductor 142. The _four induction motors 18 ₁ , 18 ₂ , 18 ₃ , and 184 are traction motors for driving electric vehicles.

The first conductor 141 is an electric wiring for electrically connecting the _{first inverter 12 1 and} the two induction motors 18 ₁ and 18 ₂ . The _second conductor 142 is an electric wiring for electrically connecting the _second inverter 122 and the _two induction motors ₁₈₃ and 184. As the _first conductor 141 and the _second conductor 142, any conductive member that can be electrically connected may be used.

The first inverter 12 ₁ and the second inverter 12 ₂ are housed in the same housing 6. The housing 6 is provided with a positive terminal P and a negative terminal N.

In the following description, when the first inverter 12 ₁ and the second inverter 12 ₂ are not distinguished, it may be referred to as "inverter 12". In addition, when the induction motors 18 ₁ , ₁₈₂ , ₁₈₃ , and ₁₈₄ are not distinguished, the term "induction motor 18" may be used.

The DC power supplied from the overhead wire 1 is supplied to the electric vehicle control device 10 via the current collector 2 and the reactor 5. Beyond the overhead line 1, there is a substation (not shown), and the overhead line 1 is positioned as an external power source when viewed from the electric vehicle control device 10. The overhead wire voltage, which is the voltage of the overhead wire 1 applied to the current collector 2, and the conversion capacity of the electric vehicle control device 10 differ depending on the drive method. The range of overhead line voltage is approximately 600 to 3000 [V]. Further, the range of the conversion capacity is several tens to several hundreds [kVA].

The positive terminal P of the electric vehicle control device 10 is connected to the reactor 5. The negative terminal N of the electric vehicle control device 10 is connected to the rail 4 via the wheel 3. As a result, the direct current due to the direct current supplied from the overhead wire 1 flows through the reactor 5, the electric vehicle control device 10, the wheels 3 and the rail 4, and returns to the substation.

In FIG. 1, an overhead electric wire is shown as an overhead wire 1, and a pantograph-shaped current collector is shown as a current collector 2, but the present invention is not limited thereto. The overhead line 1 may be the third rail used in a subway or the like, and the current collector 2 may be a current collector for the third rail in accordance with this. Further, although FIG. 1 shows a case where the overhead wire 1 is a DC overhead wire, the overhead wire 1 may be an AC overhead wire. When the overhead wire 1 is an AC overhead wire, a transformer for stepping down the AC voltage to be received is provided instead of the reactor 5, and the AC voltage output from the transformer is converted into a DC voltage in the subsequent stage of the transformer. A converter to convert is provided.

The capacitor 11 is connected between the positive terminal P and the negative terminal N inside the electric vehicle control device 10. As a result, the capacitor 11 is connected in parallel to both ends of the first inverter 12 ₁ and the second inverter 12 ₂ on the input side of the first inverter 12 ₁ and the second inverter 12 ₂ .

The capacitor 11 smoothes the applied DC voltage. Further, the capacitor 11 is connected to the reactor 5 and constitutes an LC filter circuit together with the reactor 5. This LC filter circuit suppresses the surge voltage flowing in from the overhead wire 1 side. Further, the LC filter circuit suppresses the magnitude of the ripple component of the current flowing through the inverter 12. The inverter 12 is a power conversion circuit that supplies electric power to the induction motor 18. Under the control of the control unit 20, the operation of the inverter 12 converts the DC voltage of the capacitor 11 into an AC voltage of an arbitrary frequency having an arbitrary voltage value and applies it to the corresponding induction motor 18.

FIG. 2 is a diagram showing a circuit configuration of a conventional general electric vehicle control device. In FIG. 2, the components corresponding to FIG. 1 are designated by the same reference numerals.

As shown in FIG. 2, the electric vehicle control device according to the prior art generally has a configuration in which four induction motors 18 are collectively controlled by one inverter 12. When the traction motor is an induction motor, torque is generated by slipping, which is the difference between the rotation frequency and the drive voltage frequency. By utilizing the slip peculiar to the induction motor, it is possible to control a plurality of traction motors in parallel with one inverter.

FIG. 3 is a diagram showing an arrangement example of a conventional general induction motor in an electric vehicle. In FIG. 3, the components corresponding to FIG. 2 are designated by the same reference numerals.

As shown in FIG. 3, the four induction motors 18 are separately mounted on the two bogies 24. The bogie 24 is supported by two axles 56, and the vehicle 40 is supported by two bogies 24. The torque generated in the four induction motors 18 is transmitted to the axle 56 via a speed reducer (not shown) and becomes a propulsive force for the vehicle 40.

FIG. 4 is a diagram showing a configuration example of a conventional general inverter main circuit. The inverter main circuit includes semiconductor elements UPI, VPI, WPI of the upper arm and semiconductor elements UNI, VNI, WNI of the lower arm. However, in FIG. 4, assuming that the current capacity is insufficient with a single semiconductor element, each arm connects two semiconductor elements in parallel. The same control signal is given to each semiconductor element connected in parallel.

The semiconductor element UPI and the semiconductor element UNI are connected in series to form a U-phase leg. The semiconductor element VPI and the semiconductor element VNI are connected in series to form a V-phase leg. The semiconductor element WPI and the semiconductor element WNI are connected in series to form a W-phase leg. The U-phase, V-phase, and W-phase legs are connected in parallel to each other to form a three-phase bridge circuit. In each arm, the same control signal is given to each semiconductor element connected in parallel.

FIG. 5 is a diagram used for explaining a method of generating a PWM control signal given to the semiconductor element of each arm shown in FIG. FIG. 5 shows a U-phase voltage command 26U, a V-phase voltage command 26V, and a W-phase voltage command 26W, which are sine waves, and a carrier 28, which is a triangular wave. The horizontal axis represents the phase angle, and the vertical axis represents the amplitude value. 1 [Vpu] on the vertical axis corresponds to 1/2 of the voltage amplitude applied to the inverter 12, in other words, 1/2 of the DC voltage which is the voltage of the capacitor 11.

FIG. 6 is a diagram showing PWM control signals generated by each phase voltage command shown in FIG. From the upper side, the U-phase PWM control signal, the V-phase PWM control signal, and the W-phase PWM control signal are shown in this order. The horizontal axis of FIG. 6 has the same phase angle as that of FIG.

The control unit 20 compares the U-phase voltage command 26U with the carrier 28 which is a triangular wave signal. When the U-phase voltage command 26U is larger than the carrier 28, it is “ON”, and when the U-phase voltage command 26U is the carrier 28 or less, it is “OFF”. In this way, the U-phase PWM control signal shown in the upper part of FIG. 6 is generated. Similar to the U-phase PWM control signal, the V-phase PWM control signal and the W-phase PWM control signal are also generated by comparing each of the V-phase voltage command 26V and the W-phase voltage command 26W with the carrier 28. The V-phase PWM control signal and the W-phase PWM control signal generated at this time are shown in the middle section and the lower section of FIG. 6, respectively.

FIG. 7 is a diagram showing an equivalent circuit of FIG. 2 used for explaining the leakage current. In FIG. 7, the induction motor 18 is represented by an inductance circuit symbol. When driving a three-phase motor with a three-phase inverter, not limited to an induction motor, the neutral point potential of the three-phase motor fluctuates. Therefore, as shown in FIG. 7, an equivalent circuit is formed in which the stray capacitance 34 is connected between the neutral point potential 32 of the induction motor 18 and the reference potential 31 which is the ground potential. The neutral point potential 32 contains a high frequency component due to PWM control. Therefore, when the U-phase voltage 33U, the V-phase voltage 33V, and the W-phase voltage 33W are applied to the induction motor 18, the leakage current 35 flows through the stray capacity 34.

The potential difference between the neutral point potential 32 and the reference potential 31 is called a "common mode voltage". In the case of a three-phase inverter, the common mode voltage is calculated as (Vu + Vv + Vw) / 3. However, Vu is the amplitude of the U-phase voltage 33U, Vv is the amplitude of the V-phase voltage 33V, and Vw is the amplitude of the W-phase voltage 33W.

FIG. 8 is a diagram showing a common mode voltage generated by the PWM control signal shown in FIG. In FIG. 8, the horizontal axis represents the phase angle and the vertical axis represents the amplitude of the common mode voltage.

Leakage current flows every time there is a change in the common mode voltage. Further, as shown in FIG. 8, the change of the common mode voltage occurs in a cycle shorter than the carrier cycle. Therefore, in order to suppress leakage noise, it is important to reduce the leakage current 35 flowing through the stray capacitance 34.

FIG. 9 is a diagram showing a configuration example of the inverter main circuit according to the first embodiment. The inverter main circuit according to the first embodiment has a first inverter 12 ₁ and a second inverter 12 ₂ . The first inverter 12 ₁ and the second inverter 12 ₂ are connected in parallel to both ends of the capacitor 11 on each input side.

The first inverter 12 ₁ has a U-phase leg 22U, a V-phase leg 22V, and a W-phase leg 22W for three phases in which a semiconductor element of the upper arm and a semiconductor element of the lower arm are connected in series. The U-phase leg 22U, the V-phase leg 22V, and the W-phase leg 22W are connected in parallel to each other to form a three-phase bridge circuit.

The _second inverter 122 has a semiconductor element of the upper arm and a semiconductor element of the lower arm connected in series to have three phases of the X-phase leg 22X, the Y-phase leg 22Y, and the Z-phase leg 22Z. The X-phase leg 22X, the Y-phase leg 22Y, and the Z-phase leg 22Z are connected in parallel to each other to form a three-phase bridge circuit.

As long as the total capacity of the three-phase motor is the same, the number of semiconductor elements used may be the same. In both the conventional and the first embodiment, 12 semiconductor elements are used. In the conventional example shown in FIG. 4, each arm is parallelized, whereas in the first embodiment shown in FIG. 9, the feature is that the arms are parallelized in units of inverters.

FIG. 10 is a diagram showing an arrangement example of the induction motor according to the first embodiment. In FIG. 10, the components corresponding to FIG. 1 are designated by the same reference numerals.

In FIG. 10, the first inverter 12 ₁ and the second inverter 12 ₂ are provided under the floor in the central portion of the vehicle 40 and are housed in the housing 6. Further, the _two induction motors 18 ₁ and 182 belonging to the first motor group 16 ₁ are separately mounted on the first bogie 24 ₁ and the _second bogie 242. Similarly, the _two induction motors 183 and 184 belonging to the _second motor group 162 are also separately mounted _on the first bogie 24 ₁ and the _second bogie 242. That is, one induction motor 18 ₁ belonging to the _first electric motor group 16 ₁ and one induction motor 183 belonging to the _second electric motor group 162 are mounted on the first carriage 24 ₁ . There is. Further, the _second trolley 242 is equipped with another induction motor 182 belonging to the _first electric motor group 16 ₁ and another induction motor 184 belonging to the _second electric motor group ₁₆₂ . Has been done.

With the above arrangement, the first conductor 141 is placed between the first carriage 24 ₁ and the _second carriage 242 via the _{first inverter 12 1 arranged} in the center of the vehicle 40. Will be installed. The _second conductor 142 is also installed between the first carriage 24 ₁ and the _second carriage 242 via the _second inverter 122 arranged in the central portion of the vehicle 40. When installing the _first conductor 141 and the _second conductor 142, the _first conductor 141 and the _second conductor 142 are arranged close to each other. The distance between the _first conductors 141 and the _second conductors 142 will be described later.

FIG. 11 is a diagram used for explaining variations of voltage commands given to the legs of each group and each phase in the first embodiment. (A) to (c) shown in the upper part of FIG. 11 are patterns in which the phase rotations between the groups are in the same direction. (D) to (f) shown in the lower part of FIG. 11 are patterns in which the phase rotation between the groups is in the opposite direction.

In FIG. 11, “U” represents a voltage command of the U phase, which is the first phase of the _first inverter 121. Similarly, "V" represents the voltage command of the V phase, which is the second phase of the _first inverter 121, and "W" represents the third phase of the _first inverter 121. It represents the voltage command of the W phase, which is the phase.

The voltage command of each phase is a vector, and the counterclockwise direction is the rotation direction of the vector with respect to the U phase. Further, each phase shall rotate in the order of UVW. Therefore, the V phase is a vector delayed by 120 degrees from the U phase with respect to the rotation direction, and the W phase is a vector delayed by 120 degrees (240 degrees from the U phase) with respect to the rotation direction.

Further, "X" represents a voltage command of the X phase, which is the first phase of the _second inverter 122. Similarly, "Y" represents the voltage command of the Y phase, which is the second phase of the _second inverter 122, and "Z" represents the third phase of the _second inverter 122. It represents the voltage command of the Z phase, which is the phase.

The voltage command of each phase is a vector, and the counterclockwise direction is the rotation direction of the vector with respect to the X phase. Further, it is assumed that each phase rotates in the order of XYZ. Therefore, the Y phase is a vector delayed by 120 degrees from the X phase with respect to the rotation direction, and the Z phase is a vector delayed by 120 degrees (240 degrees from the X phase) with respect to the rotation direction.

FIG. 11A is an example in which the U phase and the X phase are vectors in opposite directions, that is, the X phase is a vector having a phase difference of 180 degrees with respect to the U phase. FIG. 11B is an example in which the U phase and the Y phase are vectors in opposite directions, that is, the Y phase is a vector having a phase difference of 180 degrees with respect to the U phase. FIG. 11C is an example in which the U phase and the Z phase are vectors in opposite directions, that is, the Z phase is a vector having a phase difference of 180 degrees with respect to the U phase.

Even when the phase rotation between the groups is opposite between the UVW phase and the XYZ phase, there are three patterns as in the above (a) to (c), and from the left side of the lower part (d), (e). , (F) are shown in this order.

In any of the patterns (a) to (f) above, the three phase pairs in which any one phase of the UVW phase and one phase of the corresponding XYZ phase are combined are in an antiphase relationship. I understand.

FIG. 12 is a diagram showing a PWM control signal generated by each phase voltage command shown in FIG. 11 (a). FIG. 13 is a diagram showing an equivalent circuit of FIG. 1 used for explaining the leakage current in the first embodiment.

In FIG. 12, the first PWM control signal is a PWM control signal given to the _first inverter 121 that controls the _first motor group 161. The second PWM control signal is a PWM control signal given to the _second inverter 122 that controls the _second motor group 162.

The equivalent circuit of FIG. 1 is represented as shown in FIG. _A U-phase voltage 33U, a V-phase voltage 33V, and a W-phase voltage 33W are applied to the induction motor 181 belonging to the _first motor group 161. Since the neutral point potential 32 ₁ of the induction motor 18 ₁ fluctuates, a leakage current 35 ₁ via a stray capacitance ₃₄₁ flows between the neutral point potential 32 ₁ and the reference potential 31.

Further, an X-phase voltage 33X, a Y-phase voltage 33Y, and a Z-phase voltage _33Z are applied to the induction motor 183 belonging to the _second motor group 162. Since the neutral point potential 323 of the induction motor ₁₈₃ fluctuates _, a leakage current ₃₅₂ via the stray capacitance ₃₄₃ flows between the neutral point potential ₃₂₃ and the reference potential 31.

In FIG. 12, the U-phase PWM control signal and the X-phase PWM control signal have waveforms that are vertically inverted from each other. The relationship between the V-phase PWM control signal and the Y-phase PWM control signal, and the relationship between the W-phase PWM control signal and the Z-phase PWM control signal are also the same. That is, each phase of the first PWM control signal corresponds one-to-one with each phase of the second PWM control signal, and the paired PWM control signals have signal waveforms having opposite phases to each other.

Therefore, the relationship between the common mode voltage generated at the neutral _point potential ₃₂₁ of the induction motor 181 and the common mode voltage generated at the neutral _point potential ₃₂₃ of the induction motor 183 also becomes a vertically inverted pulse waveform. As a result, the relationship between the leakage current 351 flowing through the stray capacitance ₃₄₁ and the leakage current 352 flowing through the stray capacitance ₃₄₃ also becomes currents having opposite _phases to _each other. Further, the relationship between the leakage current 351 flowing through the _first conductor ₁₄₁ and the leakage current 352 flowing through the _second conductor 142 is also a current having opposite _phases to each other. More specifically, the directions in which the leakage current flows are opposite between each pair of the U phase and the X phase, the V phase and the Y phase, and the W phase and the Z phase. Therefore, the magnetic field created by the leakage current is canceled out in the section where the electrical wirings of the corresponding phases of each group are arranged close to each other. As a result, the voltage induced to the ground element on the ground side is suppressed.

In FIG. 13, the conductors of the U phase and the X phase, the conductors of the V phase and the Y phase, and the conductors of the W phase and the Z phase are shown close to each other. In order to cancel the magnetic field created by the leakage current, it is effective to install it as shown in FIG. As a means for installing the conductors close to each other, the conductors of the corresponding phases may be twisted and installed. If it is possible to manufacture it, the entire six conductors may be twisted.

FIG. 14 is a diagram used for explaining the distance between conductors in the first embodiment. FIG. 14 shows the cross-sectional shapes of the _two conductors 50 ₁ and 502. In _FIG . 14, the conductor 501 is, for example, _a U-phase conductor, and the conductor 502 is, for example, an X-phase conductor.

Both the conductors 50 ₁ and 50 ₂ have a conductor portion 52 and a covering portion 54 which is an insulator that covers the periphery of the conductor portion 52. The cross sections of the conductors 50 ₁ and 50 ₂ are both circular. Here, the distance between the conductors between the conductor 50 ₁ and the conductor 50 ₂ is defined as the distance between the center of the cross section of the conductor ₅₀₁ and the center of the cross section of the conductor ₅₀₂ . This distance is called the center-to-center distance and is represented by "d". Further, regarding how close the distances between the conductors are to be arranged, in the first embodiment, the relationship of the following equation (1) is satisfied with the diameter a of the conductor portion 52 as a reference length.

d ≦ 3a …… (1)

That is, in the first embodiment, the distance between the centers between the conductor _{501 and the conductor 50 2 is} 3 times or less the diameter a of the conductor portion 52.

In FIG. 14, _each cross section of the conductors 50 ₁ and 502 is circular, but the present invention is not limited to this. That is, each cross section may be non-circular. The non-circular shape may be a non-circular shape such as a polygon such as a triangle or a quadrangle, a shape formed by an ellipse or a plurality of curves.

Further, in FIG. 14, the diameters a of the conductor portions 52 in the conductors 50 ₁ and ₅₀₂ are the same, but the diameters of the conductors 52 may be different. When the cross-sectional shapes of the conductors 50 ₁ and 50 ₂ are not circular and their cross-sectional shapes are different, the content represented by the above equation (1) is as follows.

First, the distance between the centers between the conductor 50 ₁ and the conductor 50 ₂ is called the "first length" and is represented by "b". Further, the maximum length of the conductor portion in the cross section of the conductor 501 is called _{a "second length" and is represented by "c 1 "} . Further, the maximum length of the conductor portion in the cross section of the conductor ₅₀₂ is called a "third length" and is represented by "c ₂ ". At this time, the condition of the above equation (1) can be rewritten as the following equation (2).

b ≦ (c _1/2 + c _2/2 ) × 3 …… (2)

That is, in the first embodiment, the first length, which is the distance between the centers of the conductor 501 and the conductor _{50 2} , is the _second length, which is the maximum length of the conductor portion in the cross section of the conductor 501, and the conductor 50. It is 3 times or less the average value with the third length, which is the maximum length of the conductor portion in the cross section of ₂ .

Next, some points to be noted in configuring the electric vehicle control device according to the first embodiment will be described.

FIG. 15 is a diagram showing a circuit configuration of an electric vehicle control device according to a comparative example of FIG. In FIG. 15, the components corresponding to FIG. 1 are designated by the same reference numerals.

In FIG. 15, a capacitor 11 ₁ and a filter reactor 76 ₁ are connected to the DC side of the _first inverter 121. The capacitor 11 ₁ and the filter reactor 76 ₁ form a first filter circuit. Similarly, the capacitor ₁₁₂ and _the filter reactor 762 _are connected to the DC side of the _second inverter 122. The capacitor 112 and the filter reactor ₇₆₂ constitute a _second filter circuit. That is, FIG. 15 shows a configuration in which the first inverter 12 ₁ and the second inverter 12 ₂ have individual filter circuits.

As described above, in the electric vehicle control device of the first embodiment, the first inverter 12 ₁ and the second inverter 12 ₂ each perform an anti-phase switching operation. As a result, the current ripple generated on the DC side of each inverter is also out of phase. Therefore, when the filter circuits are individual, the capacitor voltage in each inverter is different between the first motor group 16 ₁ and the _second motor group 162. As a result, the symmetry of the leakage current generated from each group is broken.

On the other hand, in the configuration of FIG. 1, the capacitor is common, and the DC side of the _first inverter 121 and the DC side of the _second inverter 122 are both connected in parallel with the common capacitor. .. With this configuration, the current ripples of opposite phases generated on the DC side of each inverter are absorbed by a common capacitor. This makes it possible to maintain the symmetry of the leakage current generated from each group.

FIG. 16 is a diagram showing an arrangement example of an induction motor different from that of FIG. 10 in the first embodiment. In FIG. 16, the components corresponding to FIG. 10 are designated by the same reference numerals.

In railway vehicles, the inverter and the motor may be mounted on separate vehicles from the viewpoint of space under the floor or the weight balance of each vehicle. In this case, as shown in FIG. 16, between the vehicle 40 ₁ on which the induction motors 18 ₁ to 184 are mounted and the vehicle _{40 2} on which the first inverter 12 ₁ and the second inverter 12 ₂ are mounted. A crossover line 60, which is an electric wiring between vehicles, is laid in the vehicle.

The crossover must have a structure that flexibly deforms in consideration of running and vibration in a curved section. Therefore, the crossover is wired with slack on the ground side. Therefore, the crossover has a shorter distance between the wiring and the ground element than the wiring of other parts, and there is a high concern that the crossover will have an undesired effect on the ground element. If the method of the first embodiment described above is adopted for this problem, the leakage currents of the respective groups can be reversed in phase even in the crossover line 60. As a result, the magnetic field is canceled even in the crossover line 60, so that the voltage induced in the ground element can be suppressed.

FIG. 17 is a diagram showing a configuration example of the cooler according to the first embodiment. In FIG. 17, twelve semiconductor elements including the six semiconductor elements included in the first inverter 12 ₁ and the six semiconductor elements included in the _second inverter 122 are included in the cooler 80. An example of mounting on the fin base 82 is shown.

When the method of the first embodiment described above is used, it is preferable that the electric wiring of each group has a longer portion installed in parallel. Further, as described above, it is preferable that the _first inverter 121 and the second inverter 12 ₂ are connected to a common capacitor. Therefore, it is easy to shorten the distance between the first inverter 12 ₁ and the second inverter 12 ₂ so that the first inverter 12 ₁ and the second inverter 12 ₂ share a common cooler. become. As a result, the inverter device including the first inverter 12 ₁ and the second inverter 12 ₂ can be miniaturized.

As described above, in the electric vehicle control device according to the first embodiment, the first inverter and the induction motor belonging to the first motor group are connected by the first conductor, and the second inverter and the second inverter are connected. It is connected to the induction motor belonging to the motor group of the above by a second conductor. The first length, which is the distance between the centers of the first conductor and the second conductor between each of the first and second inverters and the carriage on which the induction motor is mounted, is the first conductor. It is set to be 3 times or less the average value of the second length, which is the maximum length of the conductor portion in the cross section of the second conductor, and the third length, which is the maximum length of the conductor portion in the cross section of the second conductor. As a result, the magnetic field created by the leakage current is canceled out, and the voltage induced in the ground element on the ground side is suppressed. In addition, leakage noise can be suppressed without relying on the addition of filter components.

In the above configuration, the first inverter and the second inverter may be housed in the same housing. As a result, the device can be miniaturized. In addition, it is possible to reduce the variation in the impedance of the leakage current path. In addition, the section in which the wiring of each group is routed independently can be shortened.

Further, in the above configuration, one capacitor for smoothing the DC voltage is used, and the DC side of the first inverter and the DC side of the second inverter are both connected in parallel with the one capacitor. You may do it. As a result, the symmetry of the output voltage between the first motor group and the second motor group is increased, so that the canceling effect of the magnetic field created by the leakage current can be enhanced.

Further, in the above configuration, the first and second conductors may be installed twisted with each other between the first or second inverter and the carriage. By twisting the first and second conductors to each other and installing them, the distance between the first conductor and the second conductor can be shortened, so that the canceling effect of the magnetic field can be enhanced.

When any one of the first inverter 12 ₁ and the second inverter 12 ₂ is stopped, it is preferable that the other inverter is also stopped. By controlling in this way, it is possible to suppress the generation of excessive leakage noise.

Embodiment 2.
FIG. 18 is a diagram showing an in-vehicle configuration of the electric vehicle control device according to the second embodiment. In FIG. 18, the components corresponding to FIG. 10 are designated by the same reference numerals.

If the ideal pulse voltage has zero rise or fall time of the pulse voltage applied from the inverter to the motor, the common mode voltage in each group is completely symmetrical. Furthermore, if the impedance of the leakage current path is also equal, the magnetic field is completely offset. However, in reality, the rise time and the fall time of the voltage waveform do not completely match due to the influence of the delay time of the gate drive circuit or the variation in the characteristics of each semiconductor element. Also, the impedance of the leakage current path does not completely match.

Therefore, in the second embodiment, as shown in FIG. 18, the _first conductor 141 and the _second conductor 142, which are the wirings of each group, are covered with the same duct 70. In the second embodiment, the duct 70 is used as a shield member.

By covering the wiring of each group with the same duct 70, it is possible to shield the magnetic field that remains without being offset. Further, since a slight magnetic field component that affects the surroundings can be shielded, the influence on the ground element can be reduced. Covering with the same duct also has the effect of preventing the impedance of the leakage current path of each group from fluctuating. Needless to say, the number of parts can be reduced as compared with installing ducts individually for each group of wiring.

Further, FIG. 19 is a diagram showing a configuration inside the vehicle of the electric vehicle control device according to the modified example of the second embodiment. In FIG. 19, the components corresponding to FIG. 16 are designated by the same reference numerals.

Since ducts cannot be installed in the crossover section, ducts will be installed in other parallel sections. _FIG . 19 shows an example in which the duct 701 is installed in the vehicle ₄₀₁ and the duct ₇₀₂ is installed in the vehicle ₄₀₂ except for the section of the crossover line 60. From the viewpoint of suppressing the variation in leakage impedance, it is desirable that the length of the section in which the wiring of each group is housed in the duct is equal. In other words, the shorter the difference in wiring length in which the wiring of each group is housed in the duct, the better.

As described above, in the electric vehicle control device according to the second embodiment, the first and second conductors are covered with the same shield member between the first or second inverter and the carriage. .. As a result, the shield member shields the magnetic field that is not offset, so that the influence on the ground element can be reduced. In addition, it is possible to suppress variations in the impedance of the leakage current path of each group.

Embodiment 3.
FIG. 20 is a diagram showing a configuration around a carriage of the electric vehicle control device according to the third embodiment. In FIG. 20, the components corresponding to FIG. 10 are designated by the same reference numerals.

FIG. 20 is a view of the _first bogie 241 shown in FIG. 10 viewed from the rail side. In FIG. 20, the wheels 57, the axle 56 connecting the wheels 57, the first bogie 24 ₁ supported by the axle 56, and the two induction motors 18 ₁ mounted on the first bogie 24 ₁ are shown. ₁₈₃ is shown. Further, the _two induction motors 18 ₁ and 183 are shown with a motor connection portion 58 which is an electrical connection portion with the _first conductor 141 or the _second conductor 142. In the following description, the motor connection portion 58 of the induction motor belonging to the first motor group 16 ₁ is referred to as a “first motor connection portion”, and the motor connection in the induction motor belonging to the _second motor group 162 The part 58 may be referred to as a "second motor connection part".

In the vicinity of the motor connection portion 58 of the _two induction motors 18 ₁ and 183, there is a portion where the _first conductor 141 and the _second conductor 142 cannot be installed in parallel. In the third embodiment, the section where the wiring of each group is not parallel is made as small as possible. Specifically, the vehicle is passed through _an intermediate position L between the motor connection portion 58 of the induction motor ₁₈₁ and the motor connection portion 58 of the induction motor 183 with respect to the traveling direction of the vehicle. Then, it is branched at the intermediate position L and connected to each motor connecting portion 58. As a result, the section in which the _first conductor 141 and the _second conductor 142 are parallel to each other becomes long, so that the magnetic field component that remains without being offset can be reduced. As a result, the influence of the leakage current on the ground element can be reduced even in the vicinity of the motor connection portion 58.

Embodiment 4.
FIG. 21 is a diagram showing a configuration of an inverter connection portion in the electric vehicle control device according to the fourth embodiment. In the inverter connection portion 64, the _{first terminal portion 661 for connecting the first conductor 141 to the first inverter 121 1 and the} second conductor 142 are connected to the _second inverter 12 ₂ . It is provided with a _second terminal portion 662 for the purpose. The _first terminal portion 661 has three terminals composed of U, V, and W, and the _second terminal portion 662 has three terminals composed of X, Y, and Z. The inverter connection unit 64 can be constructed on any surface of the housing 6 for accommodating the first inverter 12 ₁ and the second inverter 12 ₂ .

In FIG. 21, the inverter connection portion 64 has a horizontally long rectangular shape. The U, V, and W terminals in the _first terminal portion 661 are arranged so as to be arranged at equal intervals in the longitudinal direction on the first side 68 side of the two long sides of the inverter connection portion 64. There is. Further, the X, Y, and Z terminals in the _second terminal portion 662 are arranged so as to be arranged at equal intervals in the longitudinal direction on the second side 69 side of the two long sides of the inverter connection portion 64. Has been done. In FIG. 21, the X terminal is displaced in the longitudinal direction with respect to the U terminal, but the positions in the longitudinal direction may be the same. The same applies to the relationship between the Y terminal and the V terminal, and the relationship between the Z terminal and the W terminal.

Further, as shown in FIG. 21, the center distance between the U terminal and the V terminal is _d1 . Although not shown, the center distance between the V terminal and the W terminal is d ₁ , and the center distance between the U terminal and the W terminal is 2 d ₁ . Similarly, although not shown, the center distance between the X terminal and the Y terminal is d ₁ , the center distance between the Y terminal and the Z terminal is d ₁ , and the X terminal and the Z terminal The center distance between them is _2d1 . Therefore, d ₁ is the shortest distance between the phase terminals of the _first terminal portion 661 and the shortest distance between the phase terminals of the _second terminal portion 662.

Further, as shown in FIG. 21, the center distance between the U terminal and the X terminal is d ₂ . Although not shown, the center distance between the V terminal and the Y terminal and the center distance between the W terminal and the Z terminal are also d ₂ . The center distance between the U terminal and the Y terminal and the center distance between the U terminal and the Z terminal are longer than d ₂ . Further, the center distance between the X terminal and the V terminal and the center distance between the X terminal and the W terminal are also longer than d ₂ . Therefore, d ₂ is the shortest distance between the _first terminal portion 661 and the _second terminal portion 662.

Here, it is assumed that these d ₁ and d ₂ satisfy the relationship of the following equation (3).

d ₂ ≤ d ₁ …… (3)

Radiation noise generated inside the housing 6 is shielded and does not leak to the outside. On the other hand, in the vicinity of the inverter connection portion 64 to which each conductor is connected, the magnetic field generated by the leakage current may affect the ground element. Therefore, in the fourth embodiment, as in the above equation (3), the center-to-center distance between the phases in which the PWM control signals are in the opposite phase relationship is larger than the center-to-center distance between the other phases in the own group. Also, arrange each terminal so that it is equal to or less than the same. In other words, the shortest distance between the _first terminal portion 661 and the _second terminal portion 662 is the shortest distance between each phase terminal of the _first terminal portion 661, or the _second terminal portion 662. Arrange the terminals so that they are equal to or less than the shortest distance between each phase terminal. With this configuration, it is possible to suppress radiation noise radiated from the housing 6 or its surroundings that houses the first inverter 12 ₁ and the second inverter 12 ₂ .

The functions of the control unit 20 in the above-described first to fourth embodiments can be realized by the hardware configuration shown in FIG. 22 or 23. FIG. 22 is a block diagram showing an example of a hardware configuration that realizes the functions of the control unit according to the first to fourth embodiments. FIG. 23 is a block diagram showing another example of the hardware configuration that realizes the functions of the control unit according to the first to fourth embodiments.

When the function of the control unit 20 in the first embodiment is realized, as shown in FIG. 22, the processor 300 that performs the calculation, the memory 302 that stores the program read by the processor 300, and the input / output of the signal are input / output. It can be configured to include the interface 304 to be performed.

The processor 300 may be an arithmetic means such as an arithmetic unit, a microprocessor, a microcomputer, a CPU (Central Processing Unit), or a DSP (Digital Signal Processor). Further, the memory 302 includes a non-volatile or volatile semiconductor memory such as a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an EPROM (Erasable Program ROM), and an EPROM (registered trademark) (Electrically EPROM). Examples thereof include magnetic discs, flexible discs, optical discs, compact discs, mini discs, and DVDs (Digital Versailles Disc).

The memory 302 stores a program that executes the functions of the control unit 20 according to the first to fourth embodiments. The processor 300 can perform the above-mentioned processing by exchanging necessary information via the interface 304 and executing the program stored in the memory 302 by the processor 300. The calculation result by the processor 300 can be stored in the memory 302.

Further, when the function of the control unit 20 in the first to fourth embodiments is realized, the processing circuit 305 shown in FIG. 23 can also be used.

In FIG. 23, the processing circuit 305 corresponds to a single circuit, a composite circuit, an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a combination thereof. The information input to the processing circuit 305 and the information output from the processing circuit 305 can be obtained via the interface 306.

The configuration shown in the above embodiments is an example of the content of the present invention, can be combined with another known technique, and is configured without departing from the gist of the present invention. It is also possible to omit or change a part of.

1 overhead wire, 2 collector, 3,57 wheels, 4 rails, 5 reactors, 6 housings, 10 motor vehicle control devices, 11, 11 ₁ , 11 ₂ capacitors, 12 inverters, 12 ₁ first inverters, 12 ₂ 2nd inverter, 14 ₁ 1st conductor, 14 ₂ 2nd conductor, 16 ₁ 1st motor group, 16 ₂ 2nd motor group, 18, 18 ₁ , 18 ₂ , 18 ₃ , 18 ₄ induction motors , 20 control unit, 22U U phase leg, 22V V phase leg, 22WW phase leg, 22XX X phase leg, 22Y Y phase leg, 22Z Z phase leg, 24 trolley, 24 ₁ 1st trolley, 24 ₂ 2nd Cart, 26U U phase voltage command, 26V V phase voltage command, 26W W phase voltage command, 28 carrier, 31 reference potential, 32, 32 ₁ , 32 ₃ neutral point potential, 33U U phase voltage, 33V V phase voltage, 33W W-phase voltage, 33XX-phase voltage, 33YY _{- phase} voltage, _{33ZZ - phase} voltage, 34,34 1,343 Floating capacity, 35,35 1,352 Leakage current, _{40,40 1,402} Vehicle, 501 , 50 ₂ conductors, 52 conductors, 54 coverings, 56 axles, 58 motor connections, 60 crossovers, 64 inverter connections, 66 ₁ first terminal, 66 ₂ second terminal, 68 first Side, 69 _Second Side, 70, 70 ₁ , 702 Duct, 76 ₁ , ₇₆₂ Filter Reactor, 80 Cooler, 82 Fin Base, UNI, VNI, WNI, UPI, VPI, WPI Semiconductor Element.

Claims (10)

An electric vehicle control device that controls multiple induction motors with a single inverter.
A first inverter that controls a first group of motors including the plurality of induction motors, and a first inverter.
A second inverter that controls a second motor group composed of the plurality of induction motors, and a second inverter.
Equipped with
The induction motors belonging to the first motor group are mounted on different trolleys.
The induction motors belonging to the second motor group are mounted on different trolleys.
The first inverter and the induction motor belonging to the first motor group are connected by a first conductor.
The second inverter and the induction motor belonging to the second motor group are connected by a second conductor.
The first length, which is the distance between the centers of the first conductor and the second conductor between each of the first and second inverters and the carriage, is the first length of the first conductor. An electric vehicle characterized in that it is three times or less the average value of the second length, which is the maximum length of the conductor portion in the cross section, and the third length, which is the maximum length of the conductor portion in the cross section of the second conductor. Control device. A control unit for outputting a first pulse width modulation control signal to the first inverter and outputting a second pulse width modulation control signal to the second inverter is provided.
Each phase of the first pulse width modulation control signal corresponds one-to-one with each phase of the second pulse width modulation control signal, and the paired first and second pulse width modulation control signals are The electric vehicle control device according to claim 1, wherein the signal waveforms have opposite phases to each other. The electric vehicle according to claim 1 or 2, wherein the first and second conductors are covered with the same shield member between the first or second inverter and the bogie. Control device. The first and second conductors are described in any one of claims 1 to 3, wherein the first and second conductors are twisted and installed between the first or second inverter and the carriage. Electric vehicle control device. The induction motor belonging to the first motor group includes a first motor connection portion connected to the first conductor.
The induction motor belonging to the second motor group includes a second motor connection portion connected to the second conductor.
Claims 1 to 4 are characterized in that the first conductor and the second conductor are installed so as to pass through an intermediate position between the first motor connection portion and the second motor connection portion. The electric vehicle control device according to any one of the above items. The electric vehicle control device according to any one of claims 1 to 5, wherein the first and second inverters are housed in the same housing. The housing is
The first terminal portion to which the first conductor is connected and
A second terminal portion to which the second conductor is connected is provided.
The shortest distance between the first terminal portion and the second terminal portion is the shortest distance between each phase terminal of the first terminal portion or the shortest distance between each phase terminal of the second terminal portion. The electric vehicle control device according to claim 6, wherein the electric vehicle control device is equal to or less than the distance. The housing is provided with one capacitor that smoothes the DC voltage.
The electric vehicle control device according to claim 6 or 7, wherein the DC side of the first inverter and the DC side of the second inverter are both connected in parallel with the capacitor. The claim is characterized in that the plurality of semiconductor elements included in the first inverter and the plurality of semiconductor elements included in the second inverter are all mounted in the same cooler and cooled. The electric vehicle control device according to any one of 6 to 8. The electric vehicle control according to any one of claims 1 to 9, wherein when any one of the first and second inverters is stopped, the other inverter is also stopped. Device.

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